Bristle assembly for a brush and related method

ABSTRACT

A method of attaching a plurality of bristles each having a maximum strain that is less than 8% to a brush to form two spaced apart tufts. The method includes arranging the bristles adjacent and substantially parallel to one another to form a bristle grouping. The bristle grouping is divided longitudinally into an anchor portion flanked on both sides by a tuft portion. The anchor portion is bent in a manner that subjects the bent portion to less than about 8% strain. The bent anchor portion is inserted into and affixed to the bottom of a slot or aperture having an inside surface configured to receive the bent anchor portion of the bristle grouping and guide the tuft portions outwardly from the slot. The portion of the slot above the anchor portion and between the tuft portions may be filled with a material to separate the tuft portions.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed generally to fabricating brushes including devices for and methods of affixing bristles to brushes and more particularly to devices and methods related to installing tufts into the head of a brush.

2. Description of the Related Art

Generally, a brush includes tufts each of which is formed from a plurality of bristles. A bristle is a single strand or filament having two ends and middle portion disposed between the two ends. The bristles that form a single tuft are typically arranged longitudinally adjacent to one another into a grouping of substantially parallel bristles.

Brushes have a broad range of uses from household cleaning to dental hygiene. The materials used to construct brushes are as varied as their uses. In particular, the materials used to construct bristles very widely. However, most bristle materials share a couple of common characteristics. First, they are generally stiff and capable of standing upright without lateral support. Second, bristles generally tolerate a great deal of bending.

Bending deforms the bristle material. Deformation can be either plastic or elastic. If the deformation is elastic, the material will return to its original shape after the stress is removed. On the other hand, if the deformation is plastic, the bristle material will not return to its original shape after the stress is removed. In other words, plastic deformation permanently alters the shape of the bristle material. Plastic deformation occurs when the stress applied to the bristle material exceeds the yield strength of the material. If sufficient stress is applied, materials may fail or fracture.

Bending a bristle causes a portion of the bristle to stretch and a portion diametrically opposed to the stretched portion to compress. Strain is a measure of the amount of deformation experienced by the bristle. With respect to the stretched portion, the amount of strain experienced by the material may be determined by dividing the amount the bristle has stretched by the original length of the bristle. If the strain is large enough, the material will experience plastic deformation. If the strain is too great, the material may fracture. If the fracture is large enough, the bristle may break into two separate segments.

Bristles are frequently constructed from materials such as nylon, straw, natural hair, and metal wire that tolerate a great deal of bending. The bendibility of most bristle materials facilitates the manufacture of the brush. Referring to FIG. 1, many modern brushes are manufactured using a technique whereby a tuft 10 is formed from a bristle grouping 12 that is bent about its midpoint 14 to form a bent portion 16.

Referring to FIG. 2, two exemplary bristles 20 and 22 from bristle grouping 12 are provided to better illustrate aspects of the construction of the tuft 10. A bent portion 24 of the first bristle 20 is generally curved about a center point “P1.” The degree or angle of the curvature of the first bristle 20 may be measured by the angle “A1” formed between two radii “R1 a” and “R1 b” extending from the center point “P1” to each end 26 and 28 of the bent portion 24. A bent portion 30 of the second bristle 22 is generally curved about a center point “P2.” The angle of the curvature of the second bristle 22 may be measured by the angle “A2” formed between two radii “R2 a” and “R2 b” extending from the center point “P2” to each end 32 and 34 of the bent portion 30.

The strain experienced by bristles 20 and 22 may depend upon the angle of curvature and the radius curvature. As the angle of curvature approaches zero, the bend flattens out and the bristle becomes more straight. On the other hand, as the angle of curvature approaches 360°, the bend in the bristle approaches a complete circle. A larger the angle of curvature introduces more deformation into the bristle. When the angle of curvature is 180°, the portion of the bristles near the ends are substantially parallel to one other. As will be appreciated by those of ordinary skill in the art, bristles 20 and 22 have angles of curvature “A1” and “A2” approximating about 1800.

The strain experienced by bristles 20 and 22 also depends upon the radius of curvature. Obviously, the radius of curvature “R1 a” of the first bristle 20 is less than the radius of curvature “R2 a” of the second bristle 22. Therefore, the 180° bend is performed over a shorter segment of the first bristle 20 than the second bristle 22 causing the bent section 24 of the first bristle 20 to experience more deformation and strain than the bent section 30 of the second bristle 22.

Referring to FIG. 1, a staple 40 is used to fasten the bent portion 16 of the bristle grouping 12 to a body or head 42 of the brush. Frequently, the bent portion 16 of the bristle grouping 12 and staple 40 adjacent thereto are disposed within a single aperture 50 in the head 42 of the brush. In this manner, opposite ends of the bristle grouping 12 protrude from the single aperture 50 and form a single tuft 10. Generally, the diameter of the aperture 50 is approximately equal to the diameter of the tuft 10 protruding therefrom. The narrowness of the aperture 50 generally maintains a small radius of curvature in the bent portion 16 of each bristle.

The radius of curvature may determine the amount of strain experienced by each bristle and consequently the amount of deformation experienced by the bristle material. Generally, the smaller the radius of curvature, the more strain is experienced by the bristle. Because most brush making processes bend the bristle grouping about a small radius of curvature maintained by the sidewalls of a narrow aperture, the bristles are subjected to a great deal of strain.

Many materials that exhibit excellent qualities such as shape memory alloy, super elastic memory wire, and nitinol wire are difficult to fabricate into brushes because they cannot tolerate the strain involved in traditional methods of manufacture. As described in U.S. Pat. No. 6,442,785 issued to Robinson incorporated herein by reference, shape memory alloy is an excellent material for making brushes because the material is extremely durable and hydrophobic in nature, which renders it more hygienic. Super elastic memory wire has a composition substantially similar to shape memory alloy; however, super elastic memory wire exhibits somewhat different properties. Specifically, super elastic memory wire is not temperature sensitive. In other words, the temperature of super elastic memory wire need not be increased to produce the shape memory characteristics. Consequently, it may be desirable to use super elastic memory wire to construct bristles for brushes.

However, bristles formed from either super elastic memory wire or shape memory alloy cannot undergo strain exceeding about 8% without experiencing plastic or permanent deformation. With respect to dental brushes, if the diameter of the bristle grouping is about 0.003 inches to about 0.004 inches, the aperture from which a tuft protrudes is typically about 0.04 inches in diameter. However, if this aperture size is used with bristles constructed using either super elastic memory wire or shape memory alloy, the strain experienced by the outer wires of the bristle grouping will be about or exceed 8%. Bristles located more centrally within the grouping may experience even greater strain because the radius of curvature is smaller the closer the bristle is located to the center of the grouping. Therefore, the bristles may kink or break near the location of the bend. Consequently, dental brushes with super elastic memory wire or shaped memory alloy bristles cannot be manufactured using traditional brush making methods described herein.

Therefore, a need exists for methods and devices related to constructing brushes with bristles that cannot tolerate a small bend radius. A need also exists for a method of constructing a brush using bristles constructed from super elastic memory wire, shape memory alloy, nitinol wire, and the like.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)

FIG. 1 is an illustration of a tuft constructed using a prior art method.

FIG. 2 is an illustration showing the angles and radii of curvature of two bristles within the tuft of FIG. 1.

FIG. 3 is a perspective view of a brush constructed in accordance with the present invention with the bristles removed to provide a better view of the bristle assemblies.

FIG. 4 is a perspective view of three of the bristle assemblies of the brush depicted in FIG. 3 with the leftmost bristle assembly exploded to provide a better view of its components, and the bristles removed from the center bristle assembly to provide a better view of the bristle fastener and slot.

FIG. 5A is an enlarged front view of a bristle fastener for use with the bristle assemblies of FIG. 4.

FIG. 5B is a top view of the bristle fastener of FIG. 5A.

FIG. 5C is a side view of the bristle fastener of FIG. 5A.

FIG. 6 is a fragmentary, cross-sectional view of an alternate embodiment of a slot for use with the bristle assemblies of FIG. 4.

FIG. 7 is a fragmentary, perspective view of an alternate embodiment of the bristle assembly for use with the brush depicted in FIG. 3.

FIG. 8 is a fragmentary, perspective view of an alternate embodiment of the bristle assembly depicted in FIG. 7.

FIG. 9 is an exploded perspective view of an alternate embodiment of a brush constructed in accordance with the present invention.

FIG. 10 is a longitudinal cross-sectional view of the brush of FIG. 9.

FIG. 11 is a perspective view of three bristle assemblies constructed in accordance with another embodiment of the present invention with the leftmost bristle assembly exploded to provide a better view of its components, and the bristles removed from the center bristle assembly to provide a better view of the bristle fastener and slot.

FIG. 12 is an enlarged a cross-sectional view of the right most bristle assembly of FIG. 11 taken substantially along the line 12-12 of FIG. 11.

FIG. 13 is a partial exploded perspective sectional view of a brush constructed in accordance with yet another embodiment of the present invention with the bristles and staple shown for only one of the bristle assemblies to provide a better view of the bristle assemblies constructed in accordance with the present invention.

FIG. 14 is a partial longitudinal cross-sectional view of the brush of FIG. 13.

FIG. 15 is a partial cross-sectional view of the brush of FIGS. 13 and 14 taken substantially along at the line 15 of FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the present invention include a brush, bristle assembly, and methods related thereto. FIG. 3 provides an exemplary embodiment of a brush 60 to aid the illustration of an embodiment of the present invention. While brush 60 is depicted as a dental brush, it is appreciated by those of ordinary skill in the art that brush 60 may include other types of brushes such as hair brushes, cleaning brushes, and the like. Those of ordinary skill appreciate that alternate embodiments of dental brushes and other types of brushes are well known in the art and within the scope of the present invention. The brush 60 includes a brush head 62 integrally formed with a handle 64. The brush head 62 has a surface 66 from which the bristles protrude; although, the bristles have been removed from brush 60 in FIG. 3 to provide a better view of the plurality of bristle assemblies 100 included in the head 62.

Referring to FIG. 4, three substantially identical bristle assemblies 100 constructed in accordance with the present invention may be viewed. Each bristle assembly includes two spaced apart tuft portions 102 and 104 formed from a single bristle grouping 110. Because the bristle assemblies 100 are substantially identical, identical reference numbers have been used to identify like components in each of the bristle assemblies 100. A bristle grouping 110 is not shown in the middle bristle assembly 100 to provide a better view of other aspects of the bristle assembly 100. An exploded view of the leftmost bristle assembly 100 is provided to illustrate an exemplary embodiment of the components of the bristle assembly 100.

As used herein, the term “bristle grouping” refers to a plurality of bristles arranged longitudinally adjacent to one another into a grouping of substantially parallel bristles. In one embodiment, the bristle grouping 110 may include about 20 to about 30 bristles. Each bristle may be about 0.002 inches to about 0.005 inches in diameter. The bristle grouping 110 may be divided longitudinally into three sections, the two tufts or tuft portions 102 and 104 and an anchor portion 112 therebetween. The bristle grouping 110 also includes two ends 106 and 108 and a longitudinal surface 118 that extends between the two ends 106 and 108.

The bristle assembly 100 may include a bristle fastener 300 inserted into a bristle cavity or slot 400. An enclosed channel 200 is defined between the bristle fastener 300 and the slot 400. The anchor portion 112 of the bristle grouping 110 may be disposed within the enclosed channel 200. The tuft portions 102 and 104 exit the enclosed channel 200 through a pair of spaced apart exit apertures 202 and 204 (best viewed with respect to the center bristle assembly 100 of the three bristle assemblies 100 depicted in FIG. 4). A portion of the enclosed channel 200 may be curved to define an arcuate portion 206. The anchor portion 112 of the bristle grouping 110 disposed within the enclosed channel 200 may be bent by the arcuate portion 206 forming a bent portion in the anchor portion 112. The arcuate portion 206 may be shaped to provide an angle of curvature that ranges from about 1700 to about 190° and preferably is about 180°. The arcuate portion 206 may have a radius of curvature determined by the yield stress of the bristles within the bristle grouping 110. Further, because some materials such as shape memory alloy and super elastic memory wire can withstand only about 8% strain, the radius of curvature of the arcuate portion 206 of the enclosed channel 200 may be large enough to ensure the anchor portion 112 of the bristle grouping does not experience strain above or about 8%.

Referring to the leftmost bristle assembly 100 depicted in FIG. 4, the slot 400 will now be described. While the slot 400 depicted in the drawings has a generally U-shaped longitudinal cross-sectional shape, it is appreciated by those of ordinary skill in the art that other configurations of slot 400 are within the scope of the present invention. The slot 400 may be defined in the head 62 of the brush 60.

The slot 400 may be defined between two confronting sidewalls 402 and 404. A width “W” (see FIG. 3) of the slot 400 may be defined as the distance between the confronting sidewalls 402 and 404. A transverse surface 406 extends transversely between the sidewalls 402 and 404 and forms the bottom of slot 400. The slot 400 may include an opening 401 into which the bristle grouping 110 may be inserted. A length “L” (see FIG. 3) of the slot 400 may be defined as the distance between the portion of the transverse surface 406 near the opening 401 that forms a portion of the spaced apart exit aperture 202 and the portion of the transverse surface 406 near the opening 401 that forms a portion of the spaced apart exit aperture 204. A depth of the slot 400 may be defined as the largest vertical distance between the opening 401 and the lowest most portion of the transverse surface 406.

Optionally, the transverse surface 406 may be contoured in the direction parallel to the longitudinal direction of the bristle grouping 110. In the embodiment depicted in the drawings, the contour of the transverse surface 406 in the longitudinal direction may include a continuous curve having a predetermined radius of curvature “r1” (see FIG. 4). In one embodiment, the radius of curvature “r1” is large enough to avoid subjecting any of the bristles within the bristle grouping 110 to stresses that exceed the yield stresses of the bristles. The radius of curvature “r1” may also be large enough to avoid straining the bristles more than about 8%. In one embodiment, the radius of curvature “r1” is large enough to avoid straining the bristles more than about 2% to about 3%.

Optionally, the transverse surface 406 may be contoured along the transverse direction (i.e., orthogonal to the longitudinal direction of the bristle grouping 110) to maintain the bristles of the grouping in a generally cylindrical bundle or other desired shape. For example, the transverse surface 406 may include a groove 408. The groove 408 may be shaped and sized to receive a portion of the longitudinal surface 118 of the bristle grouping 110. The groove 408 may extend the full distance between sidewall 402 and 404.

The slot 400 may include a connector 420. In one embodiment, connector 420 includes two female locking elements 422 and 423 integrally formed in the sidewalls 402 and 404, respectively. In the embodiment depicted in FIG. 4, the female locking element 422 is a notch or recess formed in the sidewall 402 and the female locking element 423 is a notch or recess formed in the sidewall 404. Each of the recesses may include a generally vertical outwardly tapered inside surface 424 that intersects with a horizontal stop wall 426. In this manner, each of the recesses extends further into the sidewalls of the brush 10 nearer the opening 401 than nearer the bottom of the slot 400. While one embodiment of female locking elements 422 and 423 has been described, it is appreciated by those of ordinary skill in the art that alternate embodiments are within the scope of the present invention.

Referring to FIGS. 5A-5C, one embodiment of the bristle fastener 300 will now be described. The bristle fastener 300 is configured to be received within the slot 400. In embodiments including a U-shaped slot 400, the bristle fastener 300 may also be generally U-shaped. The bristle fastener 300 may include sidewalls 320 and 321. In embodiments where the slot 400 includes the connector 420, sidewalls 320 and 321 may include components configured to interface with the connector 420. For example, sidewalls 320 and 321 may include male locking elements 322 and 323, respectively, configured to be inserted into female locking elements 422 and 423, respectively. Each of the male locking elements 322 and 323 may include a relieved portion with a sloped generally vertical outwardly tapered wall 324 that intersects with a generally horizontal stop wall 326. In this manner, the male locking elements 322 and 323 may be wider nearer their tops than nearer their bottoms. When fully inserted into the slot 400, the male locking elements 322 and 323 are received into the female locking elements 422 and 423, respectively, with the stop walls 326 of the male locking elements 322 and 323 in juxtaposition with the stop walls 426 of the female locking elements 422 and 423, respectively, to retain the bristle fastener 300 in the slot 400. The structure of male locking elements 322 and 323 is well known in the art. While one embodiment of the connector 420 has been described herein, it will be appreciated by those of ordinary skill in the art that the invention is not limited by the connector 420 and alternate embodiments of the connector are within the scope of the present invention.

The bristle fastener 300 includes a bristle receiving surface 310. The bristle receiving surface 310 may be contoured in the direction parallel to the longitudinal direction of the bristle grouping 110. In the longitudinal direction, the contour of the bristle receiving surface 310 may include a continuous curve having a predetermined radius of curvature “r2.” In one embodiment, the radius of curvature “r2” is large enough to avoid subjecting any of the bristles within the grouping 110 to stresses that exceed the yield stresses of the bristles. The radius of curvature “r2” may also be large enough to avoid straining the bristles more than about 8%. In one embodiment, the radius of curvature “r2” is large enough to avoid straining the bristles more than about 2% to about 3%.

Optionally, the bristle receiving surface 310 may be contoured along the transverse direction (i.e., orthogonal to the longitudinal direction of the bristle grouping 110) to maintain the bristles within the grouping 110 in a generally cylindrical bundle or other desired shape. Optionally, bristle receiving surface 310 may include a groove 312. The groove 312 may be shaped and sized to receive a portion of the longitudinal surface 118 of the bristle grouping 110. The groove 312 may extend the full distance between sidewall 320 and 321, or alternatively, rails 330 and 332 may be disposed along opposing sides of the groove 312.

Referring back to FIG. 4, the anchor portion 112 of the bristle grouping 110 may be received along the bristle receiving surface 310 of the bristle fastener 300. Then, the bristle fastener 300 may be inserted into the slot 400 with the bristle grouping 110 disposed between the bristle receiving surface 310 and the transverse surface 406 of the slot 400. The bristle receiving surface 310 of the bristle fastener 300 may bias the longitudinal surface 118 of the bristle grouping 110 against the transverse surface 406 of the slot 400. The tuft portions 102 and 104 may protrude from exit apertures 202 and 204 formed between the bristle receiving surface 310 and the transverse surface 406 of the slot 400. A top portion 305 of the bristle fastener 300 between the portions of the bristle receiving surface 310 located at opposite ends of the enclosed channel 200 and defining a portion of each of the exit apertures 202 and 204 spaces the tuft portion 102 from the tuft portion 104.

In an alternate embodiment, a conventional staple (not shown) is used to affix the anchor portion 112 of the bristle grouping 110 within the slot 400. The space inside the slot 400 above the anchor portion 112 of the bristle grouping 110 may be filled with a suitable filler material such as silicon and the like. If the material used to construct the bristles is sufficiently resistant to bending, instead of permanently deforming, the bristles will attempt to straighten within the slot 400 and may generally conform to the transverse surface 406 of the slot 400. Examples of materials sufficiently resistant to bending include super elastic memory wire, shape memory alloy, nitinol wire, and the like.

Bending the anchor portion 112 of the bristle grouping 110 introduces a minimum radius of curvature into the anchor portion 112. The minimum radius of curvature may be experienced by bristles located closest to the bristle fastener 300 (or staple if one is used). To avoid exceeding the yield stresses of all of the bristles within the bristle grouping 110 and/or maximum strain the individual bristles can withstand, it may be desirable to determine the minimum radius of curvature that an individual bristle may experience before plastic deformation and/or failure occurs. The transverse surface 406 of the slot 400 may be configured to provide a minimum radius of curvature approximately equal to or greater than the predetermined minimum radius of curvature of a single bristle. The bristle fastener 300 may be configured to introduce a bend into the anchor portion 112 of the bristle grouping 110 that has radius of curvature that is approximately equal to or greater than the predetermined minimum radius of curvature of a single bristle.

The width “W” (see FIG. 3) of the slot 400 may be determined by the width or diameter of the bristle grouping 110. In one embodiment, the width “W” of the slot 400 may be about 0.04 inches at the opening 401. In another embodiment, the sidewalls 402 and 404 of the slot 400 may slope to define a slot that is narrower in the area adjacent to the transverse surface 406. The width of the transverse surface 406 of the slot 400 may be about 0.023 inches to about 0.04 inches.

The length “L” (see FIG. 3) of the slot 400 may be determined by the minimum radius of curvature of the material used to construct the bristles. For example, in some embodiments, the length “L” is at least twice the minimum radius of curvature of the material used to construct the bristles. In one embodiment, the length of the slot 400 may range from about 0.08 inches to about 0.14 inches, and is preferably about 0.128 inches.

Materials such as super elastic memory wire, shape memory alloy, nitinol wire, and the like may experience a predetermined amount of strain before the material will permanently deform or fail. Generally speaking, super elastic memory wire and shape memory alloy may experience a strain of about 8% before they undergo plastic deformation and/or fail. If a single bristle has a diameter of about 0.003 inches and is bent with a radius of curvature of about 0.05 inches or greater, the amount of strain placed on the bristles is about 2% to about 3%. In one embodiment, the transverse surface 406 is curved in the longitudinal direction and has a radius of the curvature “r1” (see FIG. 4) of about 0.05 inches or greater. In this manner, when the bristle grouping 110 is biased against and/or conforming to the transverse surface 406, the portion of the bristle grouping 110 located at and near the bend will not experience plastic deformation and/or failure.

In some embodiments, the degree of attachment between the bristle grouping 110 and the head 62 of the brush 60 is determined by the cross-sectional area of the enclosed channel 200 formed between the bristle receiving surface 310 of the bristle fastener 300 and the transverse surface 406 of the slot 400. Reducing the cross-sectional area of the enclosed channel 200 will cause greater pressure to be exerted on the bristle grouping 110 rendering the attachment between the anchor portion 112 and the brush head 62 stronger. Alternatively, a looser attachment may be achieved by increasing the cross-sectional area of the enclosed channel 200. The shape of the enclosed channel 200 may be modified to strengthen or loosen the attachment of the anchor portion 112 to the head 62. Further, gripping projections, texture, or the like may be included along the transverse surface 406 of the slot 400 and/or the bristle receiving surface 310 of the bristle fastener 300 which form the inside surface of the enclosed channel 200 to provide additional friction between the bristle grouping 110 and the inside surface of the enclosed channel 200.

Referring to FIG. 6, an alternate embodiment of the slot 400 b will be described. The slot 400 b differs from slot 400 only with respect to the contour of the transverse surface 406 b and its effects on the cross-sectional shape of the enclosed channel 200 b. The transverse surface 406 b includes a longitudinally extending ridge 409. The ridge 409 reduces the space between the transverse surface 406 b and the bristle receiving surface 310 of the bristle fastener 300. In this manner, the cross-sectional shape and size of the enclosed channel 200 b is modified to exert greater pressure on the anchor portion 112 of the bristle grouping 110 when the bristle fastener 300 is inserted into the slot 400 b.

Referring back to FIG. 4, when the bristle fastener 300 is inserted into the slot 400, two tuft portions 102 and 104 protrude from the surface 66 of the brush 60. The distance between the tuft portions 102 and 104 is determined by the portion of the bristle fastener 300 disposed therebetween. The exit angle “α” of each of the tuft portions 102 and 104 is determined by the shape of the enclosed channel 200. As is apparent to one of ordinary skill in the art, the exit angle “α” of each tuft portion 102 and 104 may be modified by simply modifying the shape of the portion of the enclosed channel 200 near each exit aperture 202 and 204. While the exit angle “α” of the tuft portions 102 and 104 depicted in the drawings is approximately 90°, it is understood by those of ordinary skill in the art that alternate angles are within the scope of the invention. Specifically, acute or obtuse exit angles may be useful to position the tuft portions 102 and 104 to reach between teeth, back teeth, or inside the crevices of teeth.

The depth of the slot 400 may be determined by exit angle “α” and/or the desired amount of spread of the tuft portions 102 and 104. A shallow slot 400 may receive a shorter anchor portion 112 making the tuft portions 102 and 104 longer. Longer tufts may fan out more readily than shorter tufts. In one embodiment, the depth of the slot 400 may range from about 0.1 inches to about 0.16 inches, and is preferably about 0.120 inches.

An alternate embodiment of the bristle assembly 100 is shown in FIG. 7, and includes a single aperture 600 with substantially vertical walls 620 and a rounded bottom 610 within which the anchor portion 112 of the bristle grouping 110 is received. The aperture 600 extends into the brush head 62 along a substantially vertical axis. A cross-section of the aperture 600 taken along a plane orthogonal to the vertical axis may have a generally circular shape. The depth of aperture 600 may range from about 0.12 inches to about 0.2 inches. The diameter of aperture 600 may range from about 0.12 inches to about 0.18 inches. A conventional staple or other fastener 640 may be used to attach the anchor portion 112 of the bristle grouping 110 to the rounded bottom 610 of the aperture 600. Attaching the anchor portion 112 to the rounded bottom 610 may bend the anchor portion 112 and form a bent portion therein. If the material used to construct the bristles is sufficiently resistant to bending, the bristles will attempt to straighten within the aperture 600 and may generally conform to the rounded bottom 610 and vertical walls 620 of the aperture 600. Examples of materials sufficiently resistant to bending include super elastic memory wire, shape memory alloy, nitinol wire, and the like. Any empty space within the aperture 600 may be filled with a suitable adhesive and/or filler material 650 such as silicon and the like.

Referring to FIG. 8, a second pair of bristle tuft portions 103 and 105 of another bristle grouping 110 are added to the embodiment depicted in FIG. 7. Each of the tuft portions 102 and 104 extends upwardly along a portion of the substantially vertical walls 620 of the aperture 600. The portion of the vertical walls 620 along which tuft portion 102 extends is opposite that along which tuft portion 104 extends. Similarly, the second pair of tuft portions 103 and 105 may extend upwardly along portions of the substantially vertical walls 620 of the aperture 600 that are opposite one another. The first pair of tuft portions 102 and 104 may be spaced from the second pair of tuft portions 103 and 105 to provide four equally spaced apart tuft portions 102, 103, 104, and 105. One or more fasteners 640 may be used to attach the anchor portions 112 of both bristle groupings 110 to the rounded bottom 610 of the aperture 600.

While the tuft portions 102 and 104 depicted in the drawings are approximately equal in height, it is apparent to those of ordinary skill in the art that the anchor portion 112 may be located closer to one end of the bristle than to the other. In this manner, tuft portions 102 and 104 having two different heights may be constructed. Alternatively, the tuft portions 102 and 104 may be trimmed or otherwise cut to achieve a desired tuft height. The ends 106 and 108 may be shaped by trimming, cutting, or otherwise modifying the ends of the individual bristles within the bristle grouping 110. In one embodiment, the ends 106 and 108 of the bristle grouping 110 are trimmed after the bristles are attached to the brush by the method discussed herein.

The tuft portions 102 and 104 may be arranged in pairs along the outer surface of a brush, including the brush 60 depicted in FIG. 3. While an exemplary arrangement of the bristle assemblies 100 within the head 62 of the brush 60 has been provided for illustrative purposes, it is apparent to those of ordinary skill in the art that alternate arrangements of bristle assemblies 100 are possible and within the scope of the present invention.

Referring to FIGS. 3 and 4, a method of constructing the bristle assembly 110 of the present invention will now be described. The minimum radius of curvature about which a single bristle may be bent before plastic deformation and/or a strain exceeding the maximum strain is experienced by the bristle is determined. The shape and/or size of the transverse surface 406 of the slot 400 and/or bristle receiving surface 310 of the bristle fastener 300 may be determined based upon the minimum radius of curvature of a single bristle and/or the minimum radius of curvature of the bristle grouping 110. The minimum radius of curvature of the bristle grouping 110 may depend upon the width and/or diameter of the bristle grouping 110. In one embodiment, the contour of the transverse surface includes the radius of curvature “r1” that is determined based upon the minimum radius of curvature of a single bristle and/or the minimum radius of curvature of the bristle grouping 110. In another embodiment, the contour of the bristle receiving surface 310 includes a radius of curvature “r2” that is determined based upon the minimum radius of curvature of a single bristle and/or the minimum radius of curvature of the bristle grouping 110.

The bristle grouping 110 is divided into three portions, the anchor portion 112 and the two tuft portions 102 and 104 with the anchor portion 112 located between two tuft portions 102 and 104, as described above. The tuft portions 102 and 104 each form one end portion of the bristle grouping 110. The anchor portion 112 is positioned lengthwise within the slot 400 with the tuft portions 102 and 104 extending outwardly from the slot 400. The anchor portion 112 is then fastened inside the slot 400.

The anchor portion 112 may be fastened inside the slot 400 by the bristle fastener 300 which is inserted into the slot 400 and sandwiches the anchor portion 112 of the bristle grouping 110 between the bristle receiving surface 310 of the bristle fastener 300 and the transverse surface 406 of the slot 400. When the anchor portion 112 of the bristle grouping 110 is disposed between the bristle receiving surface 310 of the bristle fastener 300 and the transverse surface 406 surface of the slot 400, two tuft portions 102 and 104 protrude from the slot 400. The two tuft portions 102 and 104 may be separated by a portion of the bristle fastener 300. Alternatively, a conventional staple or other style fastener may be used to anchor the anchor portion 112 of the bristle grouping 110 to the bottom of the slot 400. In this embodiment, the two tuft portions 102 and 104 may be separated by a bristle fastener similar to bristle fastener 300 or by air or a fill material such as filler material 650 (see FIGS. 7 and 8).

The bristle fastener 300 may be retained within the slot 400 by the connector 420 that prevents the removal of the bristle fastener 300 from the slot 400. In one embodiment, the connector 420 forms a permanent connection between the sidewalls 320 and 321 of the bristle fastener 300 and the sidewalls 402 and 404 of the slot 400, respectively. In an alternate embodiment, glue or other adhesives (not shown) such as Super Glue may be used to attach the sidewalls 320 and 321 of the bristle fastener 300 to the sidewalls 402 and 404 of the slot 400. Adhesives may also attach the anchor portion 112 of the bristle grouping 110 to the bristle receiving surface 310 of the bristle fastener 300 and/or the inside surface 410 of the slot 400.

With reference to FIGS. 9 and 10, an alternate embodiment constructed in accordance with the present invention will now be described. A brush 1000 includes a handle 1050 integrally formed with an adjacent generally hollow brush head 1100. In an alternate embodiment, the handle 1050 may be removably attached to the hollow brush head 1100. One of ordinary skill of the art will appreciate that many methods for constructing brush handles with hollow brush heads exist in the prior art and the manner of attachment or configuration of the handle 1050 relative to the hollow brush head 1100 does not limit the invention. While brush 1000 is depicted as a dental brush, it is appreciated by those of ordinary skill in the art that brush 1000 may include other types of brushes such as hair brushes, cleaning brushes, and the like.

The hollow brush head 1100 may include an opening 1102 along its top side 1120. The opening 1102 may be defined by the top edges of the vertical sidewalls 1104 disposed along the perimeter of the hollow brush head 1100. A top plate 1200 may be fastened to the top side 1120 of the hollow brush head 1100. The top plate 1200 may be sized and shaped to cover the opening 1102. The top edges of the vertical sidewalls 1104 may include a recess or lip 1112 for receiving the top plate 1200.

The top plate 1200 may include a plurality of through-holes or exit apertures 1210 extending between a generally planar top surface 1220 and a generally planar bottom surface 1230. The cross-sectional area of the exit apertures 1210 may be approximately equal to or larger than the cross-sectional area of a bristle grouping 1500. As described above, the bristle grouping 1500 has two tuft portions 1502 and 1504 with an anchor portion 1512 therebetween and two ends 1506 and 1508. In this manner, each end 1506 and 1508 of the bristle grouping 1500 may pass through one of the exit apertures 1210 and extend upwardly from the top plate 1200 to position the pair of tuft portions 1502 and 1504 in spaced apart relation exterior of the top plate 1200.

The anchor portion 1512 of the bristle grouping 1500 may be anchored to a bottom inside surface 1130 of the hollow brush head 1100 using any method known in the art including a traditional staple. In one embodiment, a tie down or loop 1300 is constructed using a staple 1400 with two ends 1402 and 1404. A portion of the staple 1400 extending from each of the ends 1402 and 1404 is inserted and/or embedded in the material forming the bottom inside surface 1130 of the hollow brush head 1100. The portions of the staple 1400 between the embedded portions extends upwardly away from the bottom surface 1130 to form the free-standing loop 1300.

In an embodiment wherein the loop 1300 is constructed using the staple 1400, the anchor portion 1512 of the bristle grouping 1500 may be cradled between the ends 1402 and 1404 of the staple 1400 before the ends 1402 and 1404 are embedded in the material forming the bottom inside surface 1130 of the hollow brush head 1100. Embedding the ends 1402 and 1404 into the bottom surface 1130 secures the anchor portion 1512 of the bristle grouping 1500 between the loop 1300 and the bottom surface 1130 and hence anchors the bristle grouping 1500 to the bottom surface 1130.

Alternatively, the loop 1300 may be constructed using any manner known in the art including a hook, eyelet, and the like. The loop 1300 for receiving the anchor portion 1512 of a bristle grouping 1500 may be installed along the bottom inside surface 1130 of the hollow brush head 1100. The anchor portion 1512 of the bristle grouping 1500 may be disposed inside the loop 1300. In one embodiment, the bristle grouping 1500 is threaded or inserted into the loop 1300. In this manner, the loop 1300 may anchor the bristle grouping 1500 to the bottom surface 1130.

The tuft portions 1502 and 1504 extend upwardly from the bottom inside surface 1130 of the hollow brush head 1100 and exit the brush head 1100 through a pair 1212 of the spaced apart exit apertures 1210 (see FIG. 10). In other words, each end 1506 and 1508 of the bristle grouping 1500 exits the hollow brush head 1100 through a separate one of the exit apertures 1210 to position the two spaced apart tuft portions 1502 and 1504 exterior to the hollow brush head 1100. The distance between the tuft portions 1502 and 1504 is determined by the spacing of the exit apertures 1210 through which the tuft portions 1502 and 1504 extend. While the exit apertures 1210 depicted in FIGS. 9 and 10 appear to be regularly spaced, it is appreciated by those of ordinary skill that irregularly spaced exit apertures 1210 are within the scope of the present invention. Further, the exit apertures 1210 need not be arranged in rows and columns as depicted in the drawings.

The distance between the exit apertures 1210 of the pair 1212 of exit apertures through which the tuft portions 1502 and 1504 extend may determine the strain placed upon the bristle grouping 1500. For example, a larger distance may introduce a larger radius of curvature into the bristle grouping 1500 than a smaller distance between the exit apertures 1210 of the pair 1212. Therefore, it may be desirable to determine the distance between the exit apertures 1210 of the pair 1212 based upon the desired maximum strain and/or minimum radius of curvature of the bristles.

Further, the location of and distance between the exit apertures 1210 of the pair 1212 may determine the exit angle of the tuft portions 1502 and 1504. Therefore, it may be desirable to determine the location of and distance between the exit apertures 1210 of the pair 1212 based upon the desired exit angle of the tuft portions 1502 and 1504.

Optionally, the hollow brush head 1100 may be filled with material (not shown) such as silicon and the like.

With reference to FIGS. 11 and 12, yet another alternate embodiment of the brush 60 constructed in accordance with the present invention will now be described. Referring to FIG. 11, three substantially identical bristle assemblies 2100 constructed in accordance with the present invention may be viewed. Because the bristle assemblies 2100 are substantially identical, identical reference numbers have been used to identify like components in each of the bristle assemblies 2100. A bristle grouping 2110 is not shown in the middle bristle assembly 2100 to provide a better view of other aspects of the bristle assembly 2100. An exploded view of the leftmost bristle assembly 2100 is provided to illustrate an exemplary embodiment of the components of the bristle assembly.

The bristle assembly 2100 includes two spaced apart tuft portions 2102 and 2104 formed from a single bristle grouping 2110. As in the other embodiments described herein, the bristle grouping 2110 may be divided longitudinally into three sections, the tufts or two tuft portions 2102 and 2104 and an anchor portion 2112 therebetween. The bristle grouping 2110 also includes two ends 2106 and 2108 and a longitudinal surface 2118 that extends between the two ends 2106 and 2108.

Referring to the leftmost bristle assembly 2100 depicted in FIG. 11, a slot 2400 defined in the head 62 of the brush 60 will now be described. The slot 2400 may be similar to the slot 400 but lacks female locking elements 422 and 423. The slot 2400 may include an opening 2401 into which the bristle grouping 2110 may be inserted. The opening 2401 may be defined between a pair of substantially vertical confronting sidewalls 2402 and 2404. A transverse surface 2406 may extend between the sidewalls 2402 and 2404 to form the bottom of the slot 2400.

A width “W” of the slot 2400 may be defined as the greatest distance between the confronting sidewalls 2402 and 2404. The width “W” of the slot 2400 may be determined by the width or diameter of the bristle grouping 2110. The diameter of the bristle grouping 2110 may be about 0.015 inches to about 0.025 inches. In one embodiment, the diameter of the bristle grouping 2110 is about 0.02 inches. In one embodiment, the width “W” of the slot 2400 may be about 0.04 inches.

Further, the sidewalls 2402 and 2404 may each include a tapered portion 2432 and 2434, respectively, formed near their intersection with the transverse surface 2406. The tapered portions 2432 and 2434 narrow the slot 2400 in the area adjacent to the transverse surface 2406. The distance between the sidewalls 2402 and 2404 near the transverse surface 2406 may be about 0.015 inches to about 0.025 inches.

A depth “D” of the slot 2400 may be defined as the largest vertical distance between the opening 2401 and the lowest most portion of the transverse surface 2406. The depth “D” of the slot 2400 may be about 0.1 inches to about 0.14 inches.

Like the slot 400, the slot 2400 may have a generally U-shaped longitudinal cross-sectional shape, but it is appreciated by those of ordinary skill in the art that other configurations of slot 2400 are within the scope of the present invention.

Optionally, the transverse surface 2406 may be contoured in the direction parallel to the longitudinal direction of the bristle grouping 2110. In the embodiment depicted in the drawings, the contour of the transverse surface 2406 in the longitudinal direction may include a continuous curve having a predetermined radius of curvature “r3.” In one embodiment, the radius of curvature “r3” is large enough to avoid subjecting any of the bristles within the bristle grouping 2110 to stresses that exceed the yield stresses of the bristles. The radius of curvature “r3” may also be large enough to avoid straining the bristles more than about 8%. In one embodiment, the radius of curvature “r3” is large enough to avoid straining the bristles more than about 2% to about 3%. In one embodiment, the radius “r3” is about 0.064 inches.

A length “L” of the slot 2400 may be defined as the largest distance between the end portions of the transverse surface 2406 across the opening 2401. The length “L” of the slot 2400 may be determined by the minimum radius of curvature of the material used to construct the bristles. For example, in some embodiments, the length “L” is at least twice the minimum radius of curvature of the material used to construct the bristles. In one embodiment, the length “L” of the slot 2400 may range from about 0.08 inches to about 0.14 inches, and is preferably about 0.128 inches.

Optionally, the transverse surface 2406 may be contoured along the transverse direction (i.e., orthogonal to the longitudinal direction of the bristle grouping 2110) to maintain the bristles of the grouping in a generally cylindrical bundle or other desired shape. For example, the transverse surface 2406 may include a groove 2408. The groove 2408 may be shaped and sized to receive a portion of the longitudinal surface 2118 of the bristle grouping 2110. The groove 2408 may extend the full distance between the tapered portions 2432 and 2434 of the sidewalls 2402 and 2404.

A staple 2600 is used to affix the anchor portion 2112 of the bristle grouping 2110 within the slot 2400. The staple 2600 may be constructed using a single metal plate. The staple 2600 may have two sides 2602 and 2604 located opposite one another and a top side 2606 located opposite a bottom side 2608. In one embodiment, the metal plate may be approximately square. The distance between the sides 2602 and 2604 (i.e., the width of the plate) may be between about 0.04 inches and about 0.08 inches. The distance between the top and bottom sides 2606 and 2608 (i.e., the height of the plate) may be between about 0.04 inches and about 0.08 inches. The distance between the faces of the plate (i.e., the thickness of the plate) may be between about 0.005 inches to about 0.020 inches. In one embodiment, the staple 2600 has a width of about 0.060 inches, a height of about 0.060 inches, and a thickness of about 0.010 inches.

The staple 2600 may be inserted in a downward direction into the opening 2401 of the slot 2400 with an orientation transverse to the slot until the bottom side 2608 of the staple 2600 engages a portion of the longitudinal surface 2118 of the anchor portion 2112 of the bristle grouping 2110. The width of the staple 2600 may be greater than the width “W” of the slot 2400. When the staple 2600 is inserted into the slot 2400, a portion of the sides 2602 and 2604 of the staple 2600 may cut into the top surface 66 of the brush 60 and into a portion of the brush head 62 below the top surface 66. The portion of the sides 2602 and 2604 of the staple 2600 may cut a downwardly extending channel 2702 along the sidewall 2402 and a downwardly extending channel 2704 along the sidewall 2404. The portion of each of the sides 2602 and 2604 of the staple 2600 that cut into the brush head 62 become embedded therein.

In an alternate embodiment, the width of the staple 2600 may be less than the distance between the sidewalls 2402 and 2404 near the opening 2401 and greater than the distance between the tapered portions 2432 and 2434 of the sidewalls 2402 and 2404 near the transverse surface 2406. A portion of each of the sides 2602 and 2604 of the staple 2600 may cut into the tapered portions 2432 and 2434 of the sidewalls 2402 and 2404 and become embedded therein.

The embedded portions of the sides 2602 and 2604 of the staple 2600 maintain the bottom side 2608 of the staple against the longitudinal surface 2118 of the anchor portion 2112 of the bristle grouping 2110 to bias the anchor portion 2112 of the bristle grouping 2110 against the transverse surface 2406 of the slot 2400. If the material used to construct the bristles is sufficiently resistant to bending, the bristle grouping 2110 may attempt to straighten within the slot 2400 and may generally conform to the transverse surface 2406 of the slot 2400. Examples of materials sufficiently resistant to bending include super elastic memory wire, shape memory alloy, nitinol wire, and the like.

Forces acting upon the staple 2600 may dislodge it and/or damage the bristles of the bristle grouping 2110 adjacent to the staple 2600. These forces may include forces applied to the tuft portions 2102 and 2104 of the bristle grouping 2110 and transferred to the staple 2600 by the anchor portion 2112. The forces acting upon the staple 2600 may also include forces internal to the bristle material such as spring forces introduced into the material by bending it and the forces exerted by shape memory alloy as it attempts to revert to its original substantially straight shape.

To counter and distribute the forces of the bristle grouping 2110 that would otherwise act upon the staple 2600, the bristle assembly 2100 may include a bristle insert 2300. The bristle insert 2300 may be sized and shaped to be received within the slot 2400 in the space above the staple 2600 and the anchor portion 2112 and between the tuft portions 2102 and 2104 of the bristle grouping 2110. The bristle insert 2300 may be constructed from an elasteromeric plastic, polypropylene, rubber, nylon, and the like. In embodiments including a U-shaped slot 2400, the bristle insert 2300 may also be generally U-shaped.

The bristle insert 2300 may include a pair of substantially vertical sidewalls 2320 and 2321 and a bristle engaging surface 2310 extending therebetween. The sidewall 2320 may include a tapered portion 2350 near the intersection of the sidewall 2320 and the bristle engaging surface 2310. The sidewall 2321 may include a tapered portion 2351 near the intersection of the sidewall 2321 and the bristle engaging surface 2310. The tapered portions 2350 and 2351 may taper inwardly to reduce the width of the bristle insert 2300 near the bristle engaging surface 2310. The tapered portions 2350 and 2351 may be adjacent to a portion of the tapered portions 2432 and 2434, respectively, when the bristle insert 2300 is fully received inside the slot 2400.

The bristle engaging surface 2310 is adjacent to the anchor portion 2112 of the bristle grouping 2110 when the bristle insert 2300 is fully received within the slot 2400. The bristle engaging surface 2310 may bias the anchor portion 2112 of the bristle grouping 2110 against the transverse surface 2406 of the slot 2400.

The bristle engaging surface 2310 may be contoured in the direction parallel to the longitudinal direction of the bristle grouping 2110. In the longitudinal direction, the contour of the bristle engaging surface 2310 may include a continuous curve having a predetermined radius of curvature “r4.” In one embodiment, the radius of curvature “r4” is large enough to avoid subjecting any of the bristles within the grouping 2110 to stresses that exceed the yield stresses of the bristles. The radius of curvature “r4” may also be large enough to avoid straining the bristles more than about 8%. In one embodiment, the radius of curvature “r4” is large enough to avoid straining the bristles more than about 2% to about 3%. In one embodiment, the radius “r4” may be about 0.044 inches.

An enclosed channel 2200 is formed between the bristle engaging surface 2310 and the transverse surface 2406. The enclosed channel 2200 may include to two exit apertures 2202 and 2204 formed where the ends of the enclosed channel 2200 intersect the top surface 66 of the brush head 62. A portion of the enclosed channel 2200 may be curved to define an arcuate portion 2206. The anchor portion 2112 of the bristle grouping 2110 disposed within the enclosed channel 2200 may be bent by the arcuate portion 2206 forming a bent portion in the anchor portion 2112. The arcuate portion 2206 may be shaped to provide an angle of curvature that ranges from about 170° to about 190° and preferably is about 180°. The arcuate portion 2206 may have a radius of curvature determined by the yield stress of the bristles within the bristle grouping 2110. Further, because some materials such as shape memory alloy and super elastic memory wire can withstand only about 8% strain, the radius of curvature of the arcuate portion 2206 of the enclosed channel 2200 may be large enough to ensure the anchor portion 2112 of the bristle grouping does not experience strain above or about 8%.

The bristle insert 2300 may include a transverse channel 2340 sized and shaped to receive the staple 2600 therein when the bristle insert 2300 is fully received inside the slot 2400. In one embodiment, the length of the channel 2340 extends the full width of bristle insert 2300 and is open along both sidewalls 2320 and 2321. The height of the channel 2340 corresponds to the vertical distance the bristle insert 2300 extends into the slot 2400. In one embodiment, the height of the channel 2340 formed in the bristle insert 2300 is sufficiently high so as to avid contact with the top side of the staple 2600 when the bristle insert is inserted into the slot 2400. The width of the channel 2340 may be greater than the thickness of the staple 2600. In other words, the cross-sectional envelope of the channel 2340 may be larger than the cross-sectional envelope occupied by the staple 2600 to avoid interfering with the staple 2600 when the bristle insert 2300 is inserted into the slot 2400 and allow the staple 2600 to be received within the channel 2340 even when the staple 2600 is inserted somewhat out of its intended position. In one embodiment, the height of the channel 2340 is about 0.07 inches and the width of the channel 2340 is about 0.03 inches.

A top surface 2360 of the bristle insert 2300 may include a cavity or slot 2362 sized and shaped to receive a tool (not shown), such as the head of a flat head or straight screwdriver. The tool may be used to insert the bristle insert 2300 into the slot 2400.

A length of the bristle insert 2300 may be defined as the distance between the ends of the bristle engaging surface 2310 adjacent to the opening 2401 when the bristle insert 2300 is received within the slot 2400. The length of the bristle insert 2300 may be determined by the minimum radius of curvature of the material used to construct the bristles. For example, in some embodiments, the length of the bristle insert 2300 is at least twice the minimum radius of curvature of the material used to construct the bristles. In one embodiment, the length of the bristle insert 2300 may range from about 0.06 inches to about 0.10 inches, and is preferably about 0.088 inches. The tapered portions 2350 and 2352 of the sidewalls 2320 and 2321 may extend along the faces of the sidewalls 2320 and 2321 about 0.02 inches to about 0.04 inches from the intersection of the sidewalls 2320 and 2321 and the bristle receiving surface 2310.

The faces of the sidewalls 2320 and 2321 of the bristle insert 2300 may be affixed to the faces of the sidewalls 2402 and 2404 of the slot 2400, respectively, by any suitable adhesive such as Super Glue. In one embodiment, a gap 2370 (see FIG. 12) is disposed between the faces of the sidewalls 2320 and 2321 and the faces of the sidewalls 2402 and 2404 to accommodate the adhesive. The distance between the faces of the adjacent sidewalls may be about 0.001 inches to about 0.004 inches.

Each of the sidewalls 2320 and 2321 of the bristle insert 2300 may include a projection or barb 2322 and 2323, respectively, best viewed in FIG. 12. In one embodiment, each of the barbs 2322 and 2323 is spaced vertically below the opening 2401 and extends the full length of the sidewall 2320 or 2321, respectively. The barbs 2322 and 2323 may have a generally V-shaped cross-sectional shape along a plane perpendicular to both the surface 66 of the brush head 62 and the face of the sidewalls 2320 and 2321. The V-shape may be formed by two intersecting surfaces, an inwardly facing surface 2324 and an outwardly facing surface 2325.

In one embodiment, the barbs 2322 and 2323 extend upwardly along the face of the sidewalls 2320 and 2321 to facility inserting the bristle insert 2300 into the slot 2400. The barbs 2322 and 2323 may also extend outwardly away from the face of the sidewalls 2320 and 2321, respectively, to position the barbs 2322 and 2323 against the sidewalls 2402 and 2404, respectively, of the slot 2400 when the bristle insert 2300 is fully received inside the slot 2400. After the bristle insert 2300 is inserted into the slot 2400, the barbs 2322 and 2323 may bear against the faces of the sidewalls 2402 and 2404 and resist the removal of the bristle insert 2300 from the slot 2400. The barbs 2322 and 2323 may help maintain the bristle insert 2300 inside the slot 2400 while the adhesive dries and/or sets. The barbs 2322 and 2323 may be constructed in any manner known in the art including molding them integrally with the sidewalls 2320 and 2321.

The tuft portions 2102 and 2104 of the bristle group 2110 may protrude from the exit apertures 2202 and 2204, respectively, formed between the bristle receiving surface 2310 and the transverse surface 2406 of the slot 2400. The bristle insert 2300 may space the tuft portion 2102 from the tuft portion 2104.

The transverse surface 2406 of the slot 2400 may be configured to provide a minimum radius of curvature approximately equal to or greater than the minimum radius of curvature that an individual bristle of the bristle grouping 2110 may experience before plastic deformation and/or failure occurs. The bristle insert 2300 may be configured to introduce a bend into the anchor portion 2112 of the bristle grouping 2110 that has radius of curvature that is approximately equal to or greater than the minimum radius of curvature that an individual bristle of the bristle grouping 2110 may experience before plastic deformation and/or failure occurs.

With reference to FIGS. 13-15, an alternate embodiment constructed in accordance with the present invention will now be described. Referring to FIG. 13, a brush 3000 includes a handle 3050 integrally formed with an adjacent generally solid brush head 3100. In an alternate embodiment, the handle 3050 may be removably attached to the solid brush head 3100. One of ordinary skill of the art will appreciate that many methods for constructing brush handles with solid brush heads exist in the prior art and the manner of attachment or configuration of the handle 3050 relative to the brush head 3100 does not limit the invention. While brush 3000 is depicted as a dental brush, it is appreciated by those of ordinary skill in the art that brush 3000 may include other types of brushes such as hair brushes, cleaning brushes, and the like.

The solid brush head 3100 may include one or more slots 3400 formed into its top surface 3102. Each of the slots 3400 may be constructed in accordance with slot 2400 depicted in FIGS. 11 and 12 and described above. Referring to FIG. 15, like slot 2400, each of the slots 3400 may include substantially vertical sidewalls 3402 and 3404 having tapered portions 3432 and 3434, respectively, that intersected with a transverse surface 3406 that extends between the sidewalls 3402 and 3404 to form the bottom of each slot 3400. Also like the slot 2400, the transverse surface 3406 of the slots 3400 may be configured to provide a minimum radius of curvature approximately equal to or greater than the minimum radius of curvature that an individual bristle of the bristle groupings 3500 may experience before plastic deformation and/or failure occurs.

Referring to FIG. 13, a bristle grouping 3500 that is substantially identical to bristle grouping 2110 (see FIGS. 11 and 12) may be affixed to the transverse surface 3406 of each of the slots 3400 in the same manner the bristle grouping 2110 is affixed to the transverse surface 2406 of the slot 2400. Like bristle grouping 2110, the bristle grouping 3500 has an anchor portion 3512 disposed between two tuft portions 3502 and 3504. Each of the tuft portions 3502 and 3504 includes one of the ends 3506 and 3508 of the bristle grouping 3500, respectively.

The top surface 3102 of the brush head 3100 may include a recessed portion 3112. The outside edges of the recessed portion 3112 may follow the contours of the perimeter of the brush head 3100 in the embodiment depicted in the figures.

The brush 3000 may include a top plate 3200 with a generally planar top surface 3220. The top plate 3200 may be sized and shaped to be received within the recessed portion 3112 of the top surface 3102 of the brush head 3100. One or more bristle inserts 3300 may be formed along the bottom surface 3230 of the top plate 3200. Each of the bristle inserts 3300 may be constructed in accordance with bristle insert 2300. Each of the bristle inserts 3300 may be positioned along the bottom surface 3230 of the top plate 3200 to be received within the slots 3400 when the top plate 3200 is received within the recessed portion 3112 in substantially the same manner bristle insert 2300 is received within the slot 2400. The top plate 3200 and the bristle inserts 3300 may be integrally formed as a single piece.

Referring to FIG. 15, like bristle inserts 2300, each of the bristle inserts 3300 may include a pair of substantially vertical sidewalls 3320 and 3321 and a bristle engaging surface 3310 extending therebetween. The sidewall 3320 may include a tapered portion 3350 near the intersection of the sidewall 3320 and the bristle engaging surface 3310. The sidewall 3321 may include a tapered portion 3351 near the intersection of the sidewall 3321 and the bristle engaging surface 3310. The tapered portions 3350 and 3351 may taper inwardly to reduce the width of the bristle inserts 3300 near the bristle engaging surface 3310. The tapered portions 3350 and 3351 may be adjacent to a portion of the tapered portions 3432 and 3434, respectively, when the bristle inserts 3300 are fully received inside the slots 3400. Also like bristle insert 2300, the bristle inserts 3300 may be configured to introduce a bend into the anchor portion 3512 of the bristle groupings 3500 that has radius of curvature that is approximately equal to or greater than the minimum radius of curvature that an individual bristle of the bristle grouping 3500 may experience before plastic deformation and/or failure occurs.

As best seen in FIG. 14, the top plate 3200 is constructed in accordance with top plate 1200 and has a generally planar top surface 3220 and a generally planar bottom surface 3230 with pairs of exit apertures 3202 and 3204 extending therebetween. In an alternative embodiment, the top surface of one or more of the bristle inserts 3300 may be affixed to the bottom surface 3230 of the top plate 3200 between exit apertures 3202 and 3204 rather than formed integral therewith. In this manner, the bristle inserts 3300 may be constructed from a different material than the top plate 3200.

The bristle engaging surface 3310 of each of the bristle inserts 3300 is adjacent to the anchor portion 3512 of a corresponding one of the bristle groupings 3500 when the top plate 3200 is positioned in the recessed portion 3112 of the brush head 3100 and the bristle inserts 3300 are fully received within the slots 3400. The bristle engaging surface 3310 may bias the anchor portion 3512 of the bristle grouping 3500 against the transverse surface 3406 of the slot 3400.

The faces of the sidewalls 3320 and 3321 of each of the bristle inserts 3300 may be affixed to the faces of the sidewalls 3402 and 3404 of each of the slots 3400, respectively, in the same manner the faces of the sidewalls 2320 and 2321 of the bristle insert 2300 were described as being affixed to the faces of the sidewalls 2402 and 2404 of the slot 2400. In one embodiment, a gap 3370 (see FIG. 15) substantially similar to gap 2370 is disposed between the faces of the sidewalls 3320 and 3321 and the faces of the sidewalls 3402 and 3404 to accommodate an adhesive material. Each of the sidewalls 3320 and 3321 of the bristle insert 3300 may include a projection or barb 3322 and 3323, respectively. The barbs 3322 and 3323 may be constructed in accordance with barbs 2322 and 2323 and may be used to maintain the bristle inserts 3300 within the slots 3400 while the adhesive sets and/or dries.

In one embodiment, the bottom surface 3230 (see FIG. 14) of the top plate 3200 between the bristle inserts 3300 is affixed to the top surface 3102 of the brush head 3100. The bottom surface 3230 may be affixed to the top surface 3102 using any adhesive suitable for affixing the faces of the sidewalls 2320 and 2321 of the bristle insert 2300 to the faces of the sidewalls 2402 and 2404 of the slot 2400.

Referring to FIGS. 13 and 14, the pairs of spaced apart through-holes or exit apertures 3202 and 3204 may be formed in the top plate 3200 near the intersection of each of the bristle engaging surfaces 3310 of the bristle inserts 3300 and the bottom surface 3230 of the top plate 3200. In this manner, the exit apertures 3202 and 3204 flank each of the bristle inserts 3300. The cross-sectional area of the exit apertures 3202 and 3204 may be approximately equal to or larger than the cross-sectional area of a bristle grouping 3500.

An enclosed channel 3700 substantially similar to enclosed channel 2200 described above is formed between the bristle engaging surface 3310 and the transverse surface 3406. The exit apertures 3202 and 3204 may be located at opposite ends of the enclosed channel 3700 and may be in communication with the interior of the enclosed channel 3700.

When the top plate 3200 is received within the recessed portion 3112 of the top surface 3102 of the brush head 3100, the ends 3506 and 3508 of the bristle grouping 3500 may pass through the exit apertures 3202 and 3204, respectively, and extend upwardly from the top plate 3200 to position the pair of tuft portions 3502 and 3504, respectively, exterior of the brush head 3100.

The tuft portions 3502 and 3504 may be positioned to be inserted into the exit apertures 3202 and 3204 by a pair of substantially orthogonal combs (not shown). For example, each of the tuft portions 3502 and 3504 may be received between the teeth of a first comb to position the tuft portions 3502 and 3504 in a first direction. The teeth may extend in a direction substantially parallel to the top surface 3502 of the brush head 3100 and substantially orthogonal to the tuft portions 3502 and 3504. Then, each of the tuft portions 3502 and 3504 may be received between the teeth of a second comb vertically spaced from the first comb to position the tuft portions 3502 and 3504 in a second direction. The teeth of the second comb may extend in a direction substantially parallel to the top surface 3102 of the brush head 3100 and substantially orthogonal to the tuft portions 3502 and 3504 and the teeth of the first comb. A portion of each of the tuft portions 3502 or 3504 may be trapped between a pair of neighboring teeth of the first and second combs. The distance between the neighboring teeth of the first and second combs may determine the amount of bristle spread occurring in the portion of the tuft portions 3502 and 3504 trapped therebetween. Further, the location of the neighboring teeth of the first and second combs may determine the position of the portion of the tuft portions 3502 and 3504 trapped therebetween.

The solid brush head 3100 may be constructed using any method and any material suitable for toothbrush construction. The top plate 3200 may be constructed from any material suitable to construct the bristle insert 2300 described above.

Because each bristle grouping 110, 1500, 2110, and 3500 is used to create two tuft portions 102 and 104, 1502 and 1504, 2102 and 2104, 3502 and 3504, respectively, fewer bristle connections are required to construct the brushes 60, 1000, and 3000. Further, larger bristles grouping 110, 1500, 2110, and 3500 than may currently be used to construct brushes may be used with the present invention. Additionally, materials stiffer and/or more brittle than those commonly used to construct brushes may now be used to construct brushes such as dental brushes. These materials include super elastic memory wire, shape memory alloy, and nitinol wire. By increasing the radius of curvature experienced by the anchor portions 112, 1512, 2112, and 3512 of the bristle groupings 110, 1500, 2110, and 3500, respectively, and distributing the forces encountered, permanent deformation including kinks and failures may be avoided.

While the brushes 60, 1000, and 3000 depicted in the drawings for illustrative purposes include only nine to twelve bristle assemblies, it is appreciated by those of ordinary skill in the art that brushes including greater or fewer bristle assemblies are within the scope of the present invention.

The foregoing described embodiments depict different components contained within, or connected with, different other components. It is to be understood that such depicted architectures are merely exemplary, and that in fact many other architectures can be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated can also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, changes and modifications may be made without departing from this invention and its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations).

Accordingly, the invention is not limited except as by the appended claims. 

1. A method of attaching bristles to a brush wherein each bristle has a maximum strain that is less than 8%, the method comprising: arranging a plurality of bristles to form a bristle grouping wherein the bristles are adjacent and substantially parallel to one another; dividing the bristle grouping longitudinally into an anchor portion flanked on both sides by a tuft portion; bending a portion of the anchor portion to form a bent portion, wherein the bent portion experiences less than about 8% strain; inserting the bent portion into a slot of the brush having an inside surface configured to receive the bent portion of the bristle grouping and guide the tuft portions outwardly from the slot; and affixing a portion of the bent portion to the inside surface of the slot.
 2. The method of claim 1, comprising biasing the anchor portion against the inside surface of the slot.
 3. The method of claim 1, comprising inserting a bristle insert having a bristle biasing surface into the slot adjacent to the anchor portion and placing the bristle biasing surface into engagement with the anchor portion with the bristle biasing surface biasing the anchor portion against the inside surface of the slot.
 4. The method of claim 3, wherein a predetermined amount of force is required to affix the portion of the bent portion to the inside surface of the slot and the bristle insert comprises a bristle biasing surface immediately adjacent to the anchor portion, the method comprising inserting the bristle insert to distribute a portion of the predetermined amount of force along the bristle biasing surface of the bristle insert.
 5. The method of claim 1, comprising filling the slot above the anchor portion and between the tuft portions.
 6. The method of claim 5, wherein filling the slot above the anchor portion and between the tuft portions comprises inserting a fastener into the slot above the anchor portion and between the tuft portions.
 7. The method of claim 6, wherein filling the slot above the anchor portion and between the tuft portions comprises inserting a bristle insert into the slot above the anchor portion and between the tuft portions.
 8. The method of claim 1, wherein affixing a portion of the bent portion to the inside surface of the slot comprises stapling the portion of the bent portion to the inside surface of the slot.
 9. The method of claim 8, comprising inserting a bristle insert having a bristle biasing surface into the slot adjacent to the anchor portion and placing the bristle biasing surface into engagement with the anchor portion with the bristle biasing surface biasing the anchor portion against the inside surface of the slot.
 10. The method of claim 9, comprising affixing the bristle insert to an inside surface of the slot.
 11. The method of claim 1, wherein affixing the portion of the bent portion to the inside surface of the slot comprises inserting a fastener into the slot adjacent to the anchor portion and between the tuft portions, and affixing the fastener to an inside surface of the slot.
 12. The method of claim 1, wherein bending the bent portion is accomplished with the bent portion experiencing less than about 3% strain.
 13. The method of claim 1, wherein bending the bent portion is accomplished with the bent portion experiencing a maximum strain of about 2%.
 14. The method of claim 1, wherein each of the bristles is constructed from super elastic memory wire.
 15. The method of claim 1, wherein each of the bristles is constructed from shape memory alloy.
 16. A dental brush comprising: a brush head coupled to a brush handle, the brush head comprising an aperture having an inside surface with a pair of opposing sides; a fastener; a plurality of bristles each having an anchor portion flanked on both sides by a tuft portion, wherein the anchor portion comprises a bent portion having a radius of curvature large enough to avoid plastically deforming each of the bristles of the plurality of bristles, the bent portion being anchored to the inside surface of the aperture of the brush head by the fastener, and the tuft portions exiting the aperture, each tuft portion being positioned along a different one of the opposing sides of the aperture with a space between the tuft portions; and a spacer disposed within the aperture and between the tuft portions, and configured to maintain the spacing between the tuft portions.
 17. The dental brush of claim 16, wherein the spacer is configured to bias the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head.
 18. The dental brush of claim 16, wherein the spacer comprises a portion of the fastener anchoring the bent portion to the inside surface of the aperture.
 19. The dental brush of claim 16, wherein the spacer comprises a bristle insert configured to be received within the slot adjacent to the fastener and between the tuft portions.
 20. The dental brush of claim 19, wherein the bristle insert is configured to engage and bias the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head.
 21. The dental brush of claim 16, wherein the spacer comprises a bristle insert with a fastener receiving recess configured to receive a portion of the fastener when the bristle insert is disposed within the slot between the tuft portions.
 22. The dental brush of claim 16, wherein the spacer has a bristle engagement surface biasing the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head, and at least one of the bristles is constructed from super elastic memory wire.
 23. The dental brush of claim 16, wherein the spacer has a bristle engagement surface biasing the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head, and at least one of the bristles is constructed from shape memory alloy.
 24. A dental brush comprising: a brush head coupled to a brush handle, the brush head comprising an aperture having an inside surface with a pair of opposing sides; a plurality of bristles each having an anchor portion flanked on both sides by a tuft portion, the anchor portion being bendable; and a spacer disposed within the aperture and between the tuft portions, and configured to maintain the spacing between the tuft portions, the spacer having a bristle engagement surface biasing the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head and bending the anchor portion with a radius of curvature large enough to avoid plastically deforming each of the bristles of the plurality of bristles, the tuft portions exiting the aperture and being held by the spacer in spaced apart positions along a different one of the opposing sides of the aperture.
 25. The dental brush of claim 24, wherein the bristles are constructed from super elastic memory wire.
 26. The dental brush of claim 24, wherein the bristles are constructed from shape memory wire.
 27. The dental brush of claim 24, wherein the inside surface of the aperture of the brush head engaged by the plurality of bristles has an arcuate portion.
 28. The dental brush of claim 24, wherein the bristle engagement surface of the spacer biasing the anchor portion of the plurality of bristles against the inside surface of the aperture of the brush head introduces less than about 8% strain into any of the plurality of bristles.
 29. A bristle assembly comprising: a grouping of bristles, the grouping comprising an anchor portion located between first and second tuft portions; and an enclosed channel comprising a first end, a second end spaced from the first end, an arcuate portion located between the first and second ends, and first and second spaced apart exit apertures, the first exit aperture being located at the first end, the second exit aperture being located at the second end, the anchor portion of the bristle grouping being secured within the enclosed channel with the arcuate portion of the enclosed channel holding the bristle grouping in a bent position, and the first tuft portion exiting the enclosed channel through the first exit aperture and the second tuft portion exiting the enclosed channel through the second exit aperture to form two separate and spaced apart tufts of bristles.
 30. The bristle assembly of claim 29, wherein the bristles are constructed from super elastic memory wire.
 31. The bristle assembly of claim 29, wherein the bristles are constructed from shape memory wire.
 32. The bristle assembly of claim 29, wherein the arcuate portion of the enclosed channel is U-shaped.
 33. The bristle assembly of claim 29, wherein the arcuate portion of the enclosed channel introduces less than about 8% strain into the bristle grouping.
 34. A dental brush comprising: a head having a plurality of slots each having an interior; a top plate having a plurality of spaced apart through-holes arranged in pairs and a plurality of bristle inserts each located between one of the pairs of spaced apart through-holes and received within the interior of one of the slots, the bristle inserts each being sized such that when within the interior of the slot a channel with an bent portion is defined with two spaced apart end openings, each in communication with one of the through-holes of the spaced apart through-holes in the top plate between which the bristle insert is located; and a plurality of bristle groupings each bristle grouping comprised of a plurality of bristles, each bristle grouping having two end portions and a bendable portion therebetween, the bendable portion of each bristle grouping being positioned within the one of the channels and anchored therein, the bristle insert defining the channel being configured to hold the bendable portion in a bent position within the slot with the two end portions of the bristle grouping extending out of the end openings of the channel and through the spaced apart through-holes in the top plate between which the bristle insert is located.
 35. The dental brush of claim 34, wherein the bendable portion of each of the plurality of bristle grouping is held in the bent position within the slot with a strain on the bristles of the bristle grouping less than approximately 8%.
 36. The dental brush of claim 34, wherein at least one bristle of each of the plurality of bristle groupings is constructed from super elastic memory wire.
 37. The dental brush of claim 34, wherein at least one bristle of each of the plurality of bristle groupings is constructed from shape memory alloy.
 38. The dental brush of claim 34, wherein the bendable portion of each of the plurality of bristle groupings is anchored within the slot by a fastener.
 39. The dental brush of claim 38, wherein the fastener is a staple.
 40. The dental brush of claim 38, wherein each of the bristle inserts includes a recess sized and positioned to receive the fastener therein.
 41. The dental brush of claim 34, wherein each of the slots each has an interior surface and each of the bristle inserts comprises a bristle biasing surface that biases the anchor portion against the interior surface of the slot into which the bristle insert is received.
 42. A method of constructing a brush comprising: constructing a brush head having a top surface with a plurality of slots each having an interior; constructing a top plate having a plurality of bristle inserts, each bristle insert being in a position corresponding to the position of one of the plurality of slots for insertion therein, being flanked by a first and a second through-hole in the top plate, and being positioned for insertion into one of the slots; obtaining a plurality of bristle groupings; dividing each of the bristle groupings longitudinally into an anchor portion flanked on both sides by a tuft portion; fastening the anchor portion of each bristle grouping within the interior of one of the slots with the tuft portions thereof extending exterior of the slot; inserting one of the tuft portions of each bristle grouping into the first through-hole flanking the bristle insert corresponding to the slot into which the anchor portion of the bristle grouping is fastened, and the other of the tuft portions of the bristle grouping into the second through-hole flanking the bristle insert corresponding to the slot into which the anchor portion of the bristle grouping is fastened; inserting each of the bristle inserts into its corresponding slot; and affixing the top plate to the brush head.
 43. The method of claim 42, wherein fastening the anchor portion of each bristle grouping within the interior of one of the slots comprises stapling the anchor portion to the interior of the slot.
 44. The method of claim 42, comprising positioning the tuft portions of the bristle grouping for insertion into the through-holes flanking the bristle insert corresponding to the slot into which the anchor portion of the bristle grouping is fastened by positioning each of the tuft portions between a pair of neighboring teeth of a comb.
 45. The method of claim 44, wherein the one tuft portion of the bristle grouping is inserted into the first through-hole flanking the bristle insert corresponding to the slot into which the anchor portion of the bristle grouping is fastened by positioning the tuft portion between a pair of neighboring teeth of a first comb in alignment with the first through-hole, and the other tuft portion of the bristle grouping is inserted into the second through-hole flanking the bristle insert corresponding to the slot into which the anchor portion of the bristle grouping is fastened by positioning the tuft portion between a pair of neighboring teeth of a second comb in alignment with the second through-hole, the first and second combs being substantially in an orthogonal orientation relative to each other. 